请选择ABC1J0]'b4y.D8N5L4d —What are you doing? -- I ____ a book.4W;X9j.g*R4V'{7o+K
A. reading4W;X9j.g*R4V'{7o+K
B. am reading4W;X9j.g*R4V'{7o+K
C. read4W;X9j.g*R4V'{7o+K